Struct BufReader

pub struct BufReader<R> { /* private fields */ }

The BufReader adds buffering to any reader using a specialized buffer.

This is very similar std::io::BufReader, but it uses a Ring for the internal buffer, and it provides a configurable low water mark.

Examples

use vmap::io::BufReader;

let sock = TcpStream::connect(srv.local_addr().unwrap())?;
let mut buf = BufReader::new(sock, 4000).expect("failed to create buffer");
let mut line = String::new();
let len = buf.read_line(&mut line)?;
assert_eq!(line, "hello\n");

Implementations

impl<R: Read> BufReader<R>

pub fn new(inner: R, capacity: usize) -> Result<Self>

Creates a new BufReader.

pub fn lowat(&self) -> usize

Get the low-water level.

pub fn set_lowat(&mut self, val: usize)

Set the low-water level.

When the internal buffer content length drops to this level or below, a subsequent call to fill_buffer() will request more from the inner reader.

If it desired for fill_buffer() to always request a read(), you may use:

let mut buf = BufReader::new(std::io::stdin(), 4096)?;
buf.set_lowat(usize::MAX);

pub fn get_ref(&self) -> &R

Gets a reference to the underlying reader.

pub fn get_mut(&mut self) -> &mut R

Gets a mutable reference to the underlying reader.

pub fn buffer(&self) -> &[u8]

Returns a reference to the internally buffered data.

pub fn into_inner(self) -> R

Unwraps this BufReader, returning the underlying reader.

Trait Implementations

impl<R> AsMut<R> for BufReader<R>

where R: Read, <BufReader<R> as Deref>::Target: AsMut<R>,

fn as_mut(&mut self) -> &mut R

Converts this type into a mutable reference of the (usually inferred) input type.

impl<R> AsRef<R> for BufReader<R>

where R: Read, <BufReader<R> as Deref>::Target: AsRef<R>,

fn as_ref(&self) -> &R

Converts this type into a shared reference of the (usually inferred) input type.

impl<R: Read> BufRead for BufReader<R>

fn fill_buf(&mut self) -> Result<&[u8]>

Returns the contents of the internal buffer, filling it with more data, via Read methods, if empty.

fn consume(&mut self, amt: usize)

Marks the given amount of additional bytes from the internal buffer as having been read. Subsequent calls to read only return bytes that have not been marked as read.

fn has_data_left(&mut self) -> Result<bool, Error>

🔬This is a nightly-only experimental API. (buf_read_has_data_left)

Checks if there is any data left to be read.

fn read_until(&mut self, byte: u8, buf: &mut Vec<u8>) -> Result<usize, Error>

Reads all bytes into buf until the delimiter byte or EOF is reached.

fn skip_until(&mut self, byte: u8) -> Result<usize, Error>

Skips all bytes until the delimiter byte or EOF is reached.

fn read_line(&mut self, buf: &mut String) -> Result<usize, Error>

Reads all bytes until a newline (the 0xA byte) is reached, and append them to the provided String buffer.

fn split(self, byte: u8) -> Split<Self>

where Self: Sized,

Returns an iterator over the contents of this reader split on the byte byte.

fn lines(self) -> Lines<Self>

where Self: Sized,

Returns an iterator over the lines of this reader.

impl<R: Read> Deref for BufReader<R>

type Target = R

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<R: Read> DerefMut for BufReader<R>

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<R: Read> Read for BufReader<R>

fn read(&mut self, buf: &mut [u8]) -> Result<usize>

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Reader has an efficient read_vectored implementation.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Reads all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Reads all bytes until EOF in this source, appending them to buf.

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>

Reads the exact number of bytes required to fill buf.

fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Pull some bytes from this source into the specified buffer.

fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Reads the exact number of bytes required to fill cursor.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R>

where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

where Self: Sized,

Creates an adapter which will read at most limit bytes from it.

impl<R: Read + Write> Write for BufReader<R>

fn write(&mut self, buf: &[u8]) -> Result<usize>

Writes a buffer into this writer, returning how many bytes were written.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize>

Like write, except that it writes from a slice of buffers.

fn write_all(&mut self, buf: &[u8]) -> Result<()>

Attempts to write an entire buffer into this writer.

fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<()>

Writes a formatted string into this writer, returning any error encountered.

fn flush(&mut self) -> Result<()>

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination.

fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.